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Original Frogs - go for 23T or 21T?

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G'day all
Probably the first of multiple questions; my brothers and I are reviving our original Frogs we got as kids in '87, I did some updates a few years ago (ESC, DSM2 RX, replacement shocks, new boots and tyres) but my brothers still have the OG fitout at present.  I'm kinda doing all the research and reporting results for them to follow my footsteps.

I got my re-re Hornet and OG Frog out to a track the other day for a shortlived test, and the Hornet blew away the frog in terms of speed, despite running a "standard" gear whilst I'd updated the Frog to the "speed" gear.  Note that I used the same battery for both.  I later took both motors out, hooked them up in turn to the Hornet's ESC, and gunned the TX; to my reasonably well trained ear the Hornet motor sounded like it was revving probably a good 20% faster than the Frog motor.  Dunno if it's just old and tired, dirty, or what, but looking at alternatives.

By all reports the cheap austar/surpass/goolrc motors are essentially all the same motor, and actually quite good.  My question is, for a Frog gearbox (with currently no issues) should we go for the 23T option, which equates to a sports tuned but apparently runs faster than those as the cheap ones have actual bearings, or should we push it more and go for a 21T?  I do have all sets of the frog gears, so can go back to "standard" or even "torque" gearing if required.  I saw a video last night where the guy built a re-re using a 19T, but he had concerns over how long the diff would last.

And yes quite definitely will be recommending an update from the MSC to ESCs for my brothers.

Any thoughts/alternatives greatly appreciated.

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Well the motor could indeed be tired and/or dirty, but most likely it was overgeared, or the gearbox or driveshafts aren't as smooth as they could be.

I think the "speed gear" on the Frog is a 19T? Try the standard 18T setup, or even the "torque" gearing (is that the same as Blackfoot gearing--16T pinion?). That old silvercan probably doesn't have enough power for the speed gear, so you've gotta gear down or at least match the Hornet's gearing if you want similar acceleration, because the Frog is a heavier car.

And speaking of the Hornet, they really made that gearbox perfect... it's one of the most friction-free drivetrains on the planet with bearings installed, while the Frog/ORV is the opposite and seems to always have more friction than it should (maybe the rubber driveshaft boots have something to do with it?)

As for hotter motors, if the ORV gearbox is any little bit loose or crunchy already, more power will only make it worse. I have an old 27T stock motor in my Mud Blaster, and the diff sounds like popcorn because everything's so worn out. Do all the cars have ball bearings everywhere possible?

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Hi El Gecko

The motors were tested with no load outside of the models, running off the one ESC and battery setup to reduce variables.  The Frog silvercan was noted to sound like it was revving significantly slower.

Prior to my last gearbox change I'd been running the torque (16:52T) gears.

Frogs originally ran ball bearings in the gearbox and plastic bearings in the axles, but I upgraded all bearings a few years ago.  No slop in my driveline, gearbox sides are flat, and I run one shim on the diff with no slippage (gears are all in good condition).

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Hmm, it does sound like your motor is just about done then. One last question: did you lube the motor bushings/armature shaft? If so, and it's still slow, it's probably cooked (pretty common with silvercans).

Since the rest of the drivetrain seems to be in good shape, you should be able to use either 23T or 21T motors with any of the gearings. I'm planning to run a 17T Trinity motor in my Frog with standard gearing, which is probably overkill. My Mud Blaster with a 27T motor will do 25mph on a wheezy old 6 cell NiMH with the torque gears installed (larger tires, though).

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